Control mechanism for stud securing apparatus



Feb. 28, 1950 w. 5. MILES CONTROL MECHANISM FOR STUD SECURI NG APPARATUS Filed Oct. 29, 1947 3 Sheets-Sheet 1 INVENTOR I 4 4 6. M455.

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I 3 mm 3 NM N a AM A 3 a \N 3 g Feb. 28, 1950 w. s. MILES 2,499,227

CONTROL MECHANISM FOR STUD SECURING APPARATUS Filed Oct. 29, 1947 3 Sheets-Sheet 2 l N\ /ENTOR #4414401 J. Mass.

ATTORNEY Feb. 28, 1950 w. 5. MILES 2,499,

CONTROL MECHANISM F OR STUD SECURING APPARATUS Filed Oct. 29, 1947 3 Sheets-Sheet 5 IN VENTOR. Ml/AM J. M155.

Patented Feb. L t. 1950 are,

amaze:

CONTROL MECHANISM FOR S SECURING APPARATUS William S. Miles, Hastings on Hudson, N. Y

asslgnor to Johns-Manvilie Corporation, New York, N. Y., a corporation of New York Application October 29, 1947, Serial No. 182,724

15 Clap. ((31. 1-47) The instant invention relates to improvements in apparatus for securing studs, bolts and similar fastening elements to structural members. The invention is particularly concerned with improvements in a tool of the type employing an explosive charge to drive the fastening element, here inafter referred to for convenience as a "stud," into the structural steel member. are of known type and consist essentially of a barrel adapted to receive the stud, an explosive charge to force the stud from the barrel, and means to fire the charge. The stud acts as a fired pro ectile and penetrates into or through the teel plate. beam, flange or other supportin member. These tools have been used to drive studs, say up to in diameter. into steel lates /2" or more in thickness to ach e' e a ri id connection, the stud actually penetrating t e late and for practical purposes being weld d to the plate. For example it has been found that a stud of /2 diameter driven into a V plate will withstand ap ro imately 14.000 lbs. direct com res ion load in either direction without movement. The joint between the stud and late is ai and water ti t.

A serious disadvanta e of the tool for use in the construction field h s been the dan er to others in the event the tool is accidentally or carele sly dischar ed when its muzz e is not held a ainst the structural member. The s ze of the powder cha e nece sarv to achieve the de ired results is such that. if t e shielding effect of the structural member is missing. the stud may be driven with lethal force for substantial distances. With the e problems in mind t e rincipal object of the invent on is the incorporation in a tool of this type of safety devices which hold the firin means inoperative except when the muzz e oi the tool is in proper relation hip with the members with which it is to be used. The safety devices of the instant invention have been designed primarily for the case where the muzzle of the gun is to v be inserted in a preformed perforation or opening in a covering sheet, such as a corrugated asbestos-cement sheet or the like, which is to be secured to a supporting beam or purlin. Accordingly a further object of the invention in the preferred embodiment is the provision of means to prevent the operation of the tool unless the or both of the controls to be specifically described hereafter may be embodied in the tool de Such tools pending upon the conditions under which it is to be employed.

A further and more specific object of the invention is the provision of a tool of the type 5 referred to including means for maintaining the firing means inoperative unless the bore of the muzzle is completely blanked ofi by a beam, plate or other underlying member. In the erection of building structures including covering sheets with the aid of the tool the sheets are laid on the purlins, beams or the like and preferably then perforated to receive the studs. If a perforation is not directly in line with the supporting member, as may be the case at least in some instances due to the ditliculty of determining the exact position of the purlin when' it is beneath the sheet, it is entirely possible, if not probable, that the stud, instead of entering and becoming welded to the member, will be deflected and act as a high velocity missile, extremely dangerous to persons and property in its path. The safety device of the instant invention is so constructed that the entire bore of the muzzle must be covered by the surface of the underlying member before the charge can be exploded whereby such dangers will be avoided.

A further object of the invention is the provision of safety mechanism for a tool of the above described type including a plurality of retractable feelers or fingers projecting beyond the barrel and so operatively connected to the firing mechanism in i such a manner that the latter is operable only when all of the fingers are retracted. Where the tool is to be inserted through a perforation in a covering sheet as described above. a further ch- Ject is the provision of a retractable member or detent extending radially from the barrel at a location opposite the covering sheet, the detent being operatively connected to the firing mechanism to prevent'operation unless the detent is in 40 retracted position.

My invention will be more fully understood and further objects and advantages thereof will become apparent when reference is made to the more detailed description of a preferred embodiment of the invention which is to follow and to the accompanying drawings in which:

. Fig. l is a longitudinal sectional view of a tool incorporating the instant invention, the tool being shown in position preparatory to firing;

Fig. 2 is a longitudinal sectional view of the muzzle of the tool illustrating the position of the muzzle during the firing operation;

Fig. 3 is a sectional view illustrating a structural connection obtained through the use of the as tool;

Fig. 4 is a sectional view taken on the line 4--l of Fig. 1;

Fig. 5 is an enlarged elevational view of the barrel of the tool rotated from the position shown in Fig. 1 to more clearly illustrate a detent element of the control mechanism and with parts broken away for clearness of illustration;

' Fig. 6 is a sectional view taken on the line 8- of Fig. 5;

Fig. 7 is an enlarged longitudinal, sectional view through the barrel of the tool;

Fig. 8 is a sectional view, on an enlarged scale, taken on the line B8 of Fig. 5;

Fig. 9 is a sectional view, onan enlarged scale, taken on the line 9-9 of Fig. 5;

Fig. 10 is a sectional view, on an enlarged scale, taken on the line III-I0 of Fig. 5; and

Fig. 11 is a perspective detail view illustrating the construction and arrangement of the control elements of the safety mechanism.

Referring now to the drawings and more particularly to Fig. 1, there is shown a tool In of the type under consideration in position to drive a stud l2 through a perforation M of a covering sheet 16, for example acorrugated asbestos-cement sheet, into a purlin or beam I 8. It will be appreciated that these particular structural elements have been selected only for the purposes of illustrating the use of thetool and the invention is not to be limited thereby.

' Tool i0 is basically of known type and includes a sectional barrel 20 including a muzzle 22, an intermediate section 24 and an upper section 26. The muzzle section has a central bore 23 divided by shoulder 25 into upper and muzzle portions of larger and smaller diameters, respectively. Intermediate section 24 includes a bore '3l in alignment with, and of the same diameter as, the upper portion of bore 3|. Upper section 28 includes lower and upper sockets separated by a perforated partition 21. Sections 22 and 24 have a screw threaded connection 28. Sections 24 and 26 are connected by a plug 32 threaded into the lower socket of section 26 and a socket formed in the upper end of section 24. The plug has a central bore opening in alignmentwith the bores of sections 22 and 24 defining a firing chamber for a powder charge 34. A head 36 closes off the upper end of the bore in plug 32 except for a perforation 38 in alignment with the perforation of partition 27, the aligned perforations forming a passage for a firing pin 50 carried by a bolt 42 constituting a part of the firing mechanism indicated generally at 44, and later to be more fully described.

Slidably mounted on upper section 25 is a reciprocable plunger 46 including a hollow sleeve 88 receiving section 26 and the upper end of section 24. Sleeve 48 includes one or more closed end slots 50. A screw 52 is threaded into the wall of section 26 to have its head lying within the slot 50 whereby the sleeve may be moved longitudinally of upper section 28 for a distance measured by the length of the slot.

Plunger 66 includes an operating handle comprising bifurcated arms 54 connected at their upper end by a grip 56. The plunger is held in its uppermost position with the head of screw 52 at the lower end of slot 50 by compression spring 58 having an end resting against partition 21 of section 26 and an upper end engaged by an end plate 62 in the sleeve.

Plunger 46 carries the firing mechanism 44, the latter including the bolt 42 and firing pin Ill, previously mentioned. Bolt 42 is threaded into the base of the plunger, as indicated at 68. Preferably a double thread is used to secure substantial endwise travel of the bolt when it is given a half turn. A trigger 68 is fixed to the bolt and is yieldably urged by a spring 10 in a direction to cause upward movement of the bolt in the threads. For ease in manipulation a. right hand thread is used whereby the trigger may be swung in a clockwise direction from a position in which its projecting arm 12 is against stop 14 to a position in which the other end of the trigger is against the stop, as illustrated in Fig. 4. The combined length of projection of the bolt and firing pin is correlated to the length of slot 50 so that, when arm 12 is against the stop and the plunger is operated, the firing pin will be retracted sufficiently that it will not explode charge 34. Rotation of the bolt by manipulation of the trigger into the position shown in dotted lines in Fig. 4 advances the bolt to such an extent that the firing pin is in position to explode the charge upon depression of the plunger.

In preparing the tool for operation the barrel sections are separated and charge 34, suitably in the form of a cartridge, is placed in the firing chamber where it is frictionally or otherwise held against head 36. A stud I2 is placed in the barrel, the stud carrying a piston-like element 18 lightly secured to its upper end and frictionally held in the lower end of the firing chamber. The parts are then reassembled and the tool is ready for operation. In operation the muzzle is placed against the structural member to which the stud is to be secured. Trigger 68 is rotated in a clockwise direction, as indicated by the arrow in Fig. 4, through approximately to advance the bolt, as previously described. With the trigger held in this position the plunger is forced downwardly against the action of spring 58, firing pin 44 exploding the cap or other detonator for charge 34. The expanding gases act on piston 16 to propel the stud forwardly of the barrel and into the supporting element. The powder charge is such as to drive the stud with sumcient force to, in eflect, weld it to the supporting member, the material of the latter flowing, as illustrated in Figs. 2 and 3, to increase the length of contact of the stud with the member. During the forward movement of the stud the element 16 is broken off by contact with shoulder 25 (see Fig. 2). It is removed when the barrel sections are separated for reloading.

The features ofthe tool and their operation as described above form no part of the instant invention, the latter being directed to the safety devices incorporated in' the tool and now to be described.

Referring now particularly to Figs. 1 and 5-11 inclusive, in accordance with the instant invention muzzle section 22 is provided with a plu-' rality of fingers or feelers 82 (three being shown), preferably equally spaced around th muzzle. Feelers 82 serve as control elements for an electrical circuit, thefeelers being operatively associated with the circuit in such a way that all must be retracted before th circuit will be closed. The electrical circuit controls the operation of trigger 68 as will be later described. In the preferred embodiment of the improved tool where it is to be employed in conjunction with covering sheets, such for example as the corrugated sheet l6 disclosed, an additional control is provided comprising a detent 88 (see particularly Figs. 5, 7 and'll) which also must be in retracted position before the electrical control circuit is closed.

Fingers 82, while they may take diiferent forms, in accordance with the instant embodiment of the invention comprise strips of metal or other suitable material of dovetail cross-section slidably mounted in surface slots 92 of corresponding cross-section (see Fig. 10) in the muzzle section. Slots 92 expand into wider and deeper recesses 93. Above the recesses the barrel is provided with an annular recess to receive a lower non-conducting, segmental ring 94 oi dielectric material, a segmental conductor ring 98 (see particularly Figs. 7,. 9 and 11) insulated from the barrel by a collar 91 of dielectric material and an upper, non-conducting ring 94. Segments of the lower insulating ring are separated opposite recesses 93 and similarly segments of the conductor ring are separated at these points but preferably to a lesser extent than the insulatdr lever I54 pivoted at I59 to the frame of the machine and having an arm I58 extending, when the circuit is open, into a position to prevent rotation of trigger 88.

The use of the tool for securing covering sheets such as corrugated sheets to an underlying beam or purlin will now be described, it being understood that the tool may be employed under other conditions. It will also be understood that the tool may be used with a variety of mumle sections 22, each dimensioned for a particular use.

In operation the tool is loaded with a stud and powder charge and the muzzle inserted in a preformed perforation I4 bored in the sheet in a position to overlie the structural member or purlin I 8, all as previously described. Perforation I4 is of a diameter to snugly receive the muzzle section. The tool is pressed downwardly until the ring to accommodate leaf springs 99 of conducting material which are carried by one of adiacent segments of the conductor ring opposite each recess 93', the springs being adapted to be pressed upwardly to electrically connect the segments. Fingers 82 carry caps I00 of non-conducting material supporting pins I02 extending substantially to the leaf springs and surrounded by springs I04, springs I04 yieldably urging the fingers downwardly, the extent of downward movement being limited by caps I00 contacting the shoulders of recesses 93.

Conductor ring 98 (see particularly Figs. 9 and 11) is of segmental construction as previously stated, and includes end segments I and I 05 and intermediate segments I08, H0 and H2. End segments I05 and I08 carry terminals for positive and negative leads, respectively, of the electrical circuit, as illustrated. Intermediate segments H0 and H2 support vertical conductors H4 and muzzle contacts the purlin, fingers 82 being retracted against the action of springs I04. This action causes pins I02 to press upwardly against leaf springs 99 and close the circuit between rin sections I05 and H2, I06 and I08, and I08 and I I0. When the muzzle of the tool is in this position detent 88 is opposite covering sheet I0, the edge of the sheet at the perforation forcing the detent inwardly to close the circuit between conductors H4 and H5. At this time the circuit is completely closed and solenoid 86 is operated to retract arm I58 of lever I54 to release trigger 88 for rotation. The charge may now be fired in the manner previously described. Stud I2 is driven I I6, respectively, the conductors lying in an axial recess in the barrel and extending in parallel but separated relationship to a point underlying the end of detent 88, the latter being secured to one of the conductors as by rivet I I8 and spaced from the other conductor. Detent 88 includes a lip I20 adapted when the detent is pressed inwardly, to close the circuit between conductors H4 and H6.

The positive and negative leads connected into segmental .ring 98 arecarried in chases I29 and I30, respectively, leading to contact plates I32 (see particularly Fig. 6) at the upper end of the section, the contact plates being on opposite sides of the section and each extending for a substantial distance circumferentially of the section. The leads are secured to their respective contact plates. The lower end of section 24 is provided with similar contact plates I34 adapted, when the sections are threaded together, to lie in contact with plates I32. The circumferential extension of the contact plates insures closing of the circuit between the barrel sections. Positive and negative-leads I36 extend upwardly from plates I94 in chases I38 in the surface of section 24 (see Figs. 5 and 11, and the composite showing of Fig. l), and are connected to contact strips I40, suitably insulated from the barrel section. Plunger section 48 carries contact plates I42 at its lower end, the contact plates lying against and adapted to ride on strips I40. Plates I42 are suitably insulated from the barrel section and are connected by leads I44 lying in chases I48, the leads extending respectively to a solenoid I50 and a source of electrical power, such as battery I52, both concealed in the handle element 58 of the tool. The core of the solenoid is connected to a by the exploding charge into the purlin flange to the position illustrated in Fig. 2. The tool may then be removed and the securing of the covering sheet completed by threading a nut I90 onto the threaded projecting end of the stud. (See Fig. 3.)

In the event that, due to carelessness or other causes, the perforation is not completely blanked off by the purlin, when the muzzle is inserted one or more of the fingers 82 will fail to contact the purlin and hence will not be retracted, with the result that the circuit will remain open and the t g er will be held against rotation to the firing position. Also, in the event the tool is merely pressed against some surface with no covering sheet present, although fingers 82 may be retracted, detent 88 will not be retracted and, hence, again the circuit will remain open to prevent operation of the tool.

The safety devices described above enable tools of the type described to be used in construction jobs with a minimum of danger to persons or property. The charge cannot be fired unless a given set of conditions is present which is present only, or at least substantially only, when the muzzle of the tool is properly positioned within a perforation of a covering sheet and against an underlying beam or purlin.

Having thus described my invention in rather full detail, it will be understood that these details need not be strictly adhered to and that various changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by the subjoined claims.

What I claim is:

1. In a tool for securing studs or the like to a supporting member, the tool including a barrel adapted to contact the supporting member, a bore in said barrel to receive a stud or the like and means for firing an explosive charge to force the stud from the barrel, the improvement comprising, means for releasably holding said firing means against operation, an element carried by a I said barrel and movable from a projecting to a retracted position,.and, an, electrical circuit in-- 'barrelto aretracted position, an electrical circuit including means for releasing saidreleasable holding means, and means closing said circuit eluding means for" releasing saidreleasable holding means under the control of said element.

' 2. In a tool for securing studs or the like to a tracted position when saidbarrel is in. contact with said supporting member, an electrical cir- -euit including means for releasing said releasable holding means when said circuit is closed,

. breaks in said circuit, and means closing said I breaks when said members are in retracted position.

3. In a tool for securing studs or the like to a supporting member, the tool including a barrel adapted to contact the supporting member and to pass through a perforation in a covering sheet to be secured thereto, a bore in said barrel to receive a stud or thelike, and means for firing an explosive charge to force the stud from the barrel, the improvement comprising, means for releasably holding said firing means a ainst oper-v to pass through a perforation in a covering sheet to be secured thereto, a bore in saidbarrel to .when, all said, members are in their retracted positions.

6. In a tool for securing studs or the like to 1 a supporting member, the tool including a barrel adapted to contact the supporting member and to pass through a perforation in a covering sheet to be secured thereto, a bore in said barrel to receive a stud or the like, and means for firing I an explosive charge to force the stud from the barrel, the improvement comprising, means for releasably holding said firing means against op- I eration, a plurality of fingers supp rted on said 1 barrel adjacent the muzzle thereof, means acting on said fingers to yieldably maintain them in positions where they project beyond the barrel,

I an electrical circuit including means for releasing said holding means, a plurality of breaks in said circuit, and means operated by said fingers to close said breaks.

- 7. Ina tool for securing studsor the like to a supporting member, the tool including a barrel adaptedto contact the supporting member and receive a stud or thelike, and means for firing an explosivecharge to force the stud from the barrel, the improvement comprising, means for releasably holding said firing means against opation, a member carried by said barrel opposite within the perforation and movable from a position where it extends radially beyond the barrel -to a retracted position, an electrical circuit including means for'releasing said releasable holdj a ing means when said circuit is closed, breaks in I said circuit, andmeans closing said breaks when said member is in retracted osition.

4. In a tool for securing studs or the like to a supporting member, the tool including a barrel adapted to contact the supporting member and to pass through a perforation in a covering sheet to be secured thereto, a bore in said barrel to receive a stud or the like and means for firing an explosive charge to force the stud from the barrel, the improvement comprising, means for releasably holding said firing means against operation, a member carried by said barrel opposite said covering sheet when the barrel is in position within the perforation and movable from a position where it extends radially beyond the barrel to a retracted position, members carried by said barrel and movable from a position of projection beyond the end of the barrel to a retracted posi. tion when said barrel is in contact with said supporting member, an electrical circuit including means for releasing said releasable holding means, and means closing said circuit when said members are in their retracted positions.

5. In a tool for securing studs or the like to a supporting member, the tool including a barrel adapted to contact the supporting member and to pass through a perforation in a covering sheet to be secured thereto, a bore in said barrel to resaid covering sheet when the barrel is inposition eration, a detent carried by'said barrel, means for yieldably urging said detent radially beyond said barreLa plurality of fingers supported on said barrel adjacent'the muzzle thereof, means acting on said fingers to yieldably maintain themin positions where they project beyond the barrel,

an electrical circuit including means for releasceive a stud or the like, and means for firing an ing said holding means, a plurality ofbreak s in said circuit, and means operated by said detent and fingers to close said breaks.

8. In a tool for securing studs or the like to a supportin member, the tool including a barrel adapted to contact the supporting member and to pass through a perforation in a covering sheet to be secured thereto, a bore in said barrel to receive a stud or the like, and means for firing an explosive charge to force the stud from the barrel, the improvement comprising, means for releasably holding said firing means against operation, a plurality of fingers supported on said barrel adjacent the muzzle thereof, means acting on said fingers to yieldably maintain them in positions where they project beyond the barrel, an electrical circuit including means for releasing said releasably holding means, a segmental conductor member in said circuit, and elements operated by said fingers to electrically connect segments of said conductor member.

9. In a tool for securin studs or the like to a supporting member, the tool including a barrel adapted to contact the supporting member and to pass through a perforation in a covering sheet to be secured thereto, a bore in said barrel to receive a stud or the like, and means for firing an explosive charge to force the stud from the barrel, the improvement comprising, means for releasably holding said firing means against operation, a detent carried by said barrel, means yieldably urging said detent radially beyond said barrel, a plurality of fingers supported on said barrel adjacent the muzzle thereof, means acting on said fingers to yieldably maintain them in positions where they project beyond the barrel, an electrical circuit including means for releasing said re-leasable holding means, a segmental conductor member in said circuit, and elements operated by said detent and fingers to electrically connect the segments of said conductor member.

10. In a tool for securing studs or the like to a supporting member, the tool including a barrel adapted to contact the supporting member and to pass through a perforation in a covering sheet to be secured thereto, a bore in said barrel to receive a stud or the like, and means for firing an explosive charge to force the stud from the barrel, the improvement comprising, means for releasably holding said firing means against operation, a plurality of fingers supported on said barrel adjacent the muzzle thereof, springs yieldably urging the fingers to project beyond the barrel, an electrical circuit includin means for releasing said releasable holding means, a segmental conductor ring in said circuit, and contact elements carried by said fingers and movable upon retraction of said fingers into position to electrically connect adjacent segments of the conductor ring.

11. In a tool for securing studs or the like to a supporting member, the tool including a barrel adapted to contact the supporting member and to pass through a perforation in a covering sheet to be secured thereto, a bore in said barrel to receive a stud or the like, and means for firing an explosive charge to force the stud from the barrel, the improvement comprising, means for releasably holding said firing means against operation, a detent carried by said barrel, spring means yieldably urging said detent radially beyond said barrel, a plurality of fingers supported on said barrel adjacent the muzzle thereof, springs yieldably urging the fingers to project beyond the barrel, an electrical circuit including means for releasing said releasable holding means, a segmental conductor ring in said circuit, and contact elements carried by said detent and fingers and movable by retraction of said detent and fingers into positions to electrically connect the segments of the conductor ring.

12. In a tool for securing studs or the like to a supporting member, the too] including a barrel. a bore in said barrel to receive a stud or the like, and means for firing an explosive charge to force said stud from the barrel, the improvement comprising, means for releasably holding said firing means against operation, a plurality of elements carried by said barrel and each movable from a projecting to a retracted pc-ition, and means operative in the retracted position of all of said elements for withdrawing said holding means to release said firing means for operation.

13. In a tool for securing studs or the like to a supporting member, the tool including a barrel having a muzzle adapted to contact the supporting member during operation of the tool, a bore in said barrel to receive a stud or the like, and means for firing an explosive charge to force said stud from the barrel, the improvement comprising, means releasably holding said firing means against operation, a plurality of elements carried by said barrel spaced around said bore and movable from a position of projection beyond the end of the barrel to a retracted position, and means operative in the retracted position of all of said elements for withdrawing said holding means to release said firing means for operation.

14. In a tool for securing studs or the like to a supporting member for the purpose of securing an overlying covering sheet to said member, the covering sheet having a perforation to receive said stud, the tool including a barrel adapted to enter said perforation and contact the supporting member, a bore in said barrel to receive a stud or the like, and means for firing an explosive charge to force the stud from the barrel, the improvement comprising, means releasably holding said firing means against operation, means in said barrel at the position of said covering sheet and movable from a projecting position to a retracted position, and means operative in the retracted position of the movable means for withdrawing said holding means to release said firing means for operation.

15. In a tool for securing studs or the like to a supporting member, the tool including a barrel adapted to contact the supporting member and to pass through a perforation in a covering sheet to be secured thereto, a bore in said barrel to receive a stud or the like, and means for firing an explosive charge to force the stud from the barrel, the improvement comprising, means for releasably holding said firing means against operation, a detent carried by said barrel opposite said covering sheet when the barrel is in position within the perforation, said detent being movable from a position in which it extends radially beyond said barrel to a retracted position, elements carried by said barrel adjacent the lower end thereof and movable from a position projecting beyond the barrel to a retracted position, and means operative in the retracted positions of said detent and said elements for withdrawing said holding means to release said firing means for operation.

WILLIAM S. MniES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

